Refer to the exhibit. HostX is transferring a file to the FTP server. Point A represents the frame as it goes toward the Toronto router. What will the Layer 2 destination address be at this point?

A.

abcd.1123.0045

B.

192.168.7.17

C.

aabb.5555.2222

D.

192.168.1.1

E.

abcd.2246.0035

Correct Answer:E

Explanation:

For packets destined to a host on another IP network, the destination MAC address will be the LAN interface of the router. Since the FTP server lies on a different network, the host will know to send the frame to its default gateway, which is Toronto.

QUESTION 12

Which two statements describe the operation of the CSMA/CD access method? (Choose two.)

In a CSMA/CD collision domain, stations must wait until the media is not in use before transmitting.

C.

The use of hubs to enlarge the size of collision domains is one way to improve the operation of the CSMA/CD access method.

D.

After a collision, the station that detected the collision has first priority to resend the lost data.

E.

After a collision, all stations run a random backoff algorithm. When the backoff delay period has expired, all stations have equal priority to transmit data.

F.

After a collision, all stations involved run an identical backoff algorithm and then synchronize with each other prior to transmitting data.

Correct Answer:BE

Explanation:

Ethernet networking uses Carrier Sense Multiple Access with Collision Detect (CSMA/CD), a protocol that helps devices share the bandwidth evenly without having two devices transmit at the same time on the network medium. CSMA/CD was created to overcome the problem of those collisions that occur when packets are transmitted simultaneously from different nodes. And trust me, good collision management is crucial, because when a node transmits in a CSMA/CD network, all the other nodes on the network receive and examine that transmission. Only bridges and routers can effectively prevent a transmission from propagating throughout the entire network! So, how does the CSMA/CD protocol work? Like this: when a host wants to transmit over the network, it first checks for the presence of a digital signal on the wire. If all is clear (no other host is transmitting), the host will then proceed with its transmission. But it doesn’t stop there. The transmitting host constantly monitors the wire to make sure no other hosts begin transmitting. If the host detects another signal on the wire, it sends out an extended jam signal that causes all nodes on the segment to stop sending data (think, busy signal). The nodes respond to that jam signal by waiting a while before attempting to transmit again. Backoff algorithms determine when the colliding stations can retransmit. If collisions keep occurring after 15 tries, the nodes attempting to transmit will then time out.

QUESTION 13

On a Cisco switch, which protocol determines if an attached VoIP phone is from Cisco or from another vendor?

A.

RTP

B.

TCP

C.

CDP

D.

UDP

Correct Answer:C

Explanation:

The Cisco Unified IP Phone uses CDP to communicate information such as auxiliary VLAN ID, per port power management details, and Quality of Service (QoS) configuration information with the Cisco Catalyst switch.

Cisco Discovery Protocol (CDP) is a proprietary protocol designed by Cisco to help administrators collect information about both locally attached and remote devices. By using CDP, you can gather hardware and protocol information about neighbor devices, which is useful info for troubleshooting the network.

CDP messages are generated every 60 seconds as multicast messages on each of its active interfaces.

The information shared in a CDP packet about a Cisco device includes the following:

Name of the device configured with the hostname command IOS software version

Refer to the exhibit. A network device needs to be installed in the place of the icon labeled Network Device to accommodate a leased line attachment to the Internet. Which network device and interface configuration meets the minimum requirements for this installation?

A.

a router with two Ethernet interfaces

B.

a switch with two Ethernet interfaces

C.

a router with one Ethernet and one serial interface

D.

a switch with one Ethernet and one serial interface

E.

a router with one Ethernet and one modem interface

Correct Answer:C

Explanation:

Only a router can terminate a leased line attachment access circuit, and only a router can connect two different IP networks. Here, we will need a router with two interfaces, one serial connection for the line attachment and one Ethernet interface to connect to the switch on the LAN.

QUESTION 15

To what type of port would a cable with a DB-60 connector attach?

A.

Serial port

B.

Console port

C.

Ethernet port

D.

Fibre optic port

Correct Answer:A

Explanation:

Serial Connection

cl_3_dte_male

cl_2_dce

The picture on the left shows a V.35 DTE cable with a male DB60 connector and a male standard 34-pin Winchester-type connector. The right picture shows a V.35 DCE serial cable with a male DB60 connector and a female 34-pin Winchester-type connector. As you probably guessed already, the male connector of the DTE cable is attached to the DCE cable’s female connector, this is depicted in the picture below. This is known as a back-to- back connection, and ‘simulates’ a WAN link. In a real world setup, the DTE cable’s male connector typically connects to a port on a CSU/DSU provided by a service provider (i.e. telco), which in turn connects to a CSU/DSU at another location, thru a T1 link for example.

The DB60 connector connects to a Serial interface on a router.

cl_4_malefemale

Reference: http://www.techexams.net/techlabs/ccna/lab_hardware.shtml

QUESTION 16

Refer to the exhibit. The output is from a router in a large enterprise. From the output, determine the role of the router.

A.

A Core router.

B.

The HQ Internet gateway router.

C.

The WAN router at the central site.

D.

Remote stub router at a remote site.

Correct Answer:D

Explanation:

Since the routing table shows only a single default route using the single interface serial 0/0, we know that this is most likely a remote stub site with a single connection to the rest of the network. All the other answer options would mean that this router would have more connections, and would contain more routes.

QUESTION 17

Which layer of the TCP/IP stack combines the OSI model physical and data link layers?

A.

Internet layer

B.

transport layer

C.

application layer

D.

network access layer

Correct Answer:D

Explanation:

The Internet Protocol Suite, TCP/IP, is a suite of protocols used for communication over the internet. The TCP/ IP model was created after the OSI 7 layer model for two major reasons. First, the foundation of the Internet was built using the TCP/IP suite and through the spread of the World Wide Web and Internet, TCP/IP has been preferred. Second, a project researched by the Department of Defense (DOD) consisted of creating the TCP/IP protocols. The DOD’s goal was to bring international standards which could not be met by the OSI model.

Since the DOD was the largest software consumer and they preferred the TCP/IP suite, most vendors used this model rather than the OSI. Below is a side by side comparison of the TCP/IP and OSI models.

QUESTION 18

Which layer of the OSI model controls the reliability of communications between network devices using flow control, sequencing and acknowledgments?

A.

Physical

B.

Data-link

C.

Transport

D.

Network

Correct Answer:C

QUESTION 19

Which protocol uses a connection-oriented service to deliver files between end systems?

A.

TFTP

B.

DNS

C.

FTP

D.

SNMP

E.

RIP

Correct Answer:C

Explanation:

TCP is an example of a connection-oriented protocol. It requires a logical connection to be established between the two processes before data is exchanged. The connection must be maintained during the entire time that communication is taking place, then released afterwards. The process is much like a telephone call, where a virtual circuit is established- -the caller must know the person’s telephone number and the phone must be answered– before the message can be delivered.

TCP/IP is also a connection-oriented transport with orderly release. With orderly release, any data remaining in the buffer is sent before the connection is terminated. The release is accomplished in a three-way handshake between client and server processes. The connection-oriented protocols in the OSI protocol suite, on the other hand, do not support orderly release. Applications perform any handshake necessary for ensuring orderly release.

Examples of services that use connection-oriented transport services are telnet, rlogin, and ftp.

QUESTION 20

Refer to the exhibit. The host in Kiev sends a request for an HTML document to the server in Minsk. What will be the source IP address of the packet as it leaves the Kiev router?

A.

10.1.0.1

B.

10.1.0.5

C.

10.1.0.6

D.

10.1.0.14

E.

10.1.1.16

F.

10.1.2.8

Correct Answer:E

Explanation:

Although the source and destination MAC address will change as a packet traverses a network, the source and destination IP address will not unless network address translation (NAT) is being done, which is not the case here.